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Around 400 BC Democritus, matter is made up of small invible particles , that come in different forms positions and arrangements.
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Isaac Newton theorized a mechanical universe with small, solid masses in motion.
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In 1766 Henry Cavendish discovers and studies hydrogen.
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Antoine Lavoisier published the first Peroidic table , with 33 chemical elements , although they were devided into gases nonmetals , metals and "earths"
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John Dalton proposes an "atomic theory" with spherical atoms based upon measurable mass
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J.Plucker Builds the first cathode ray tube , which is later instrumental in future nuclear research .
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Dmitri Mendeleev Periodic table included gaps were elements which had not been discovered , but had to exist would be , it also has rows and tables similar to current ones.His table also did not order them by atomic weight , but actually atomic number , even though atomic numbers had not been devised at the time.
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X-rays are discovered by german physicist Wilhelm Rontgen, he conducts numerous tests and expirments with his new discovery
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In 1898 Pierre and Marie Curie discover the first radioactive elements: radium and polonium
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Ernest Rutherford publishes discoveries on radiation, including alpha and beta particles
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Frederick Soddy disovers unstable Isotopes , and that some of them have half-lives , and can decay.
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Richard Abegg discoveres that Noble gasses are stable because of their electron configurations
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In 1906 Hans Gieger invents the first primitive Gieger counter , which later on can be used to detect radation , radioactive ores , and many other types of radioactive oddities.
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Niels Bohr proposed an atomic structure theory that stated the outer orbit of an atom could hold more electrons than the inner orbit.
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James Chadwick discovered neutrons, a subatomic unit which has a neutral charge and weights slightly more then a proton , and s located inside the nucleus.
